## Facts

- Lambdin P. Milligan was a civilian U.S. citizen and Indiana resident who had never served in the U.S. military or navy.
- In October 1864, during the Civil War, Milligan and others were arrested in Indiana, a loyal state where federal courts were open and functioning.
- A military commission convened in Indianapolis charged Milligan with conspiracy against the United States, aiding rebels, inciting insurrection, disloyal practices, and violations of the laws of war.
- The commission convicted Milligan and sentenced him to death.
- In May 1865, Milligan sought habeas corpus in federal circuit court, arguing the commission lacked jurisdiction over a civilian entitled to indictment and jury trial in the civil courts.
- The circuit judges divided on controlling legal questions and certified them to the Supreme Court.

## Issues

1. Whether a military commission had jurisdiction to try, convict, and sentence a civilian in a loyal state where the civil courts were open and operating.
2. Whether, under the Habeas Corpus Suspension Act of 1863, a person arrested under federal authority must be discharged if not indicted or presented by the next grand jury.

## Decision

- The Supreme Court ordered Milligan discharged from military custody.
- A majority held that the military commission lacked jurisdiction because Indiana was not invaded or in rebellion and the civil courts were open.
- The Court also concluded that, under the 1863 Suspension Act regime, continued detention was unlawful where the next grand jury convened and did not indict or present the detainee.
- A separate concurrence agreed in the result but reasoned that Congress could authorize military commissions in some circumstances even when civil courts are open; Milligan’s trial was unlawful because Congress had not authorized it.

## Legal Principles

- Military tribunals may not try civilians where Article III courts are open and able to administer criminal justice in the ordinary course.
- Constitutional guarantees of grand-jury indictment and jury trial apply to civilians and cannot be displaced by executive use of military commissions in loyal territory absent lawful authority and necessity.
- Martial law is limited to situations of actual necessity tied to active military operations and breakdown of civil authority; it does not arise merely from wartime conditions.
- Under the Habeas Corpus Suspension Act of 1863, a person arrested under its authority is entitled to discharge if not indicted or presented by the next grand jury at the first subsequent term of the relevant federal court.
- Congress controls the creation and jurisdiction of courts and the making of laws necessary to execute war-related powers; executive action cannot supply criminal jurisdiction over civilians in place of functioning civil courts.

## Conclusion

The Court held that a civilian in a loyal state could not be tried and sentenced by a military commission while the civil courts were open, and that statutory requirements tied to the 1863 suspension framework independently required discharge absent timely grand-jury action.


Ex parte Milligan, 71 U.S. (4 Wall.) 2 (1866)